2 * UCW Library -- Logging: Configuration of Log Streams
4 * (c) 2009 Martin Mares <mj@ucw.cz>
6 * This software may be freely distributed and used according to the terms
7 * of the GNU Lesser General Public License.
12 #include "ucw/log-internal.h"
14 #include "ucw/simple-lists.h"
16 #include "ucw/threads.h"
23 /*** Configuration of streams ***/
25 struct stream_config {
29 char *syslog_facility;
31 clist types; // simple_list of names
32 clist substreams; // simple_list of names
33 clist limits; // of struct limit_config's
34 int microseconds; // Enable logging of precise timestamps
38 struct log_stream *ls;
39 int mark; // Used temporarily in log_config_commit()
44 clist types; // simple_list of names
50 stream_init(void *ptr)
52 struct stream_config *c = ptr;
59 stream_commit(void *ptr)
61 struct stream_config *c = ptr;
63 if (c->file_name && c->syslog_facility)
64 return "Both FileName and SyslogFacility selected";
65 if (c->syslog_facility && !log_syslog_facility_exists(c->syslog_facility))
66 return cf_printf("SyslogFacility `%s' is not recognized", c->syslog_facility);
67 if (c->syslog_facility && c->microseconds)
68 return "Syslog streams do not support microsecond precision";
72 static const char * const level_names[] = {
79 static struct cf_section limit_config = {
80 CF_TYPE(struct limit_config),
82 #define P(x) PTR_TO(struct limit_config, x)
83 CF_LIST("Types", P(types), &cf_string_list_config),
84 CF_DOUBLE("Rate", P(rate)),
85 CF_UNS("Burst", P(burst)),
91 static struct cf_section stream_config = {
92 CF_TYPE(struct stream_config),
94 CF_COMMIT(stream_commit),
96 #define P(x) PTR_TO(struct stream_config, x)
97 CF_STRING("Name", P(name)),
98 CF_STRING("FileName", P(file_name)),
99 CF_STRING("SyslogFacility", P(syslog_facility)),
100 CF_BITMAP_LOOKUP("Levels", P(levels), level_names),
101 CF_LIST("Types", P(types), &cf_string_list_config),
102 CF_LIST("Substream", P(substreams), &cf_string_list_config),
103 CF_LIST("Limit", P(limits), &limit_config),
104 CF_INT("Microseconds", P(microseconds)),
105 CF_INT("ShowTypes", P(show_types)),
106 CF_INT("SyslogPID", P(syslog_pids)),
107 CF_INT("ErrorsFatal", P(errors_fatal)),
113 static clist log_stream_confs;
115 static struct stream_config *
116 stream_find(const char *name)
118 CLIST_FOR_EACH(struct stream_config *, c, log_stream_confs)
119 if (!strcmp(c->name, name))
125 stream_resolve(struct stream_config *c)
130 return cf_printf("Log stream `%s' has substreams which refer to itself", c->name);
134 CLIST_FOR_EACH(simp_node *, s, c->substreams)
136 struct stream_config *d = stream_find(s->s);
138 return cf_printf("Log stream `%s' refers to unknown substream `%s'", c->name, s->s);
139 if (err = stream_resolve(d))
147 log_config_commit(void *ptr UNUSED)
149 // Verify uniqueness of names
150 CLIST_FOR_EACH(struct stream_config *, c, log_stream_confs)
151 if (stream_find(c->name) != c)
152 return cf_printf("Log stream `%s' defined twice", c->name);
154 // Check that all substreams resolve and that there are no cycles
156 CLIST_FOR_EACH(struct stream_config *, c, log_stream_confs)
157 if (err = stream_resolve(c))
163 static struct cf_section log_config = {
164 CF_COMMIT(log_config_commit),
166 CF_LIST("Stream", &log_stream_confs, &stream_config),
171 static void CONSTRUCTOR
172 log_config_init(void)
174 cf_declare_section("Logging", &log_config, 0);
180 log_type_mask(clist *l)
186 CLIST_FOR_EACH(simp_node *, s, *l)
187 if (!strcmp(s->s, "all"))
192 * We intentionally ignore unknown types as not all types are known
193 * to all programs sharing a common configuration file. This is also
194 * the reason why Types is a list and not a bitmap.
196 int type = log_find_type(s->s);
198 types |= 1 << LS_GET_TYPE(type);
203 /*** Generating limiters ***/
206 * When limiting is enabled, we let log_stream->filter point to this function
207 * and log_stream->user_data point to an array of pointers to token bucket
208 * filters for individual message types.
211 log_limiter(struct log_stream *ls, struct log_msg *m)
213 struct token_bucket_filter **limits = ls->user_data;
216 struct token_bucket_filter *tbf = limits[LS_GET_TYPE(m->flags)];
220 ASSERT(!(m->flags & L_SIGHANDLER));
221 if (m->flags & L_LOGGER_ERR)
224 timestamp_t now = ((timestamp_t) m->tv->tv_sec * 1000) + (m->tv->tv_usec / 1000);
226 int res = tbf_limit(tbf, now);
233 struct log_msg mm = *m;
234 mm.flags |= L_LOGGER_ERR;
235 mm.raw_msg = "(maximum logging rate exceeded, some messages will be suppressed)";
236 log_pass_msg(0, ls, &mm);
245 log_apply_limits(struct log_stream *ls, struct limit_config *lim)
249 ls->user_data = cf_malloc_zero(LS_NUM_TYPES * sizeof(struct token_bucket_filter *));
250 ls->filter = log_limiter;
252 struct token_bucket_filter **limits = ls->user_data;
253 struct token_bucket_filter *tbf = cf_malloc_zero(sizeof(*lim));
254 tbf->rate = lim->rate;
255 tbf->burst = lim->burst;
258 uns mask = log_type_mask(&lim->types);
259 for (uns i=0; i < LS_NUM_TYPES; i++)
264 /*** Generating streams ***/
267 log_check_configured(const char *name)
269 if (stream_find(name))
272 return cf_printf("Log stream `%s' not found", name);
275 static struct log_stream *
276 do_new_configured(struct stream_config *c)
278 struct log_stream *ls;
285 ls = log_new_file(c->file_name, 0);
286 else if (c->syslog_facility)
287 ls = log_new_syslog(c->syslog_facility, (c->syslog_pids ? LOG_PID : 0));
289 ls = log_new_stream(sizeof(*ls));
291 CLIST_FOR_EACH(simp_node *, s, c->substreams)
292 log_add_substream(ls, do_new_configured(stream_find(s->s)));
294 ls->levels = c->levels;
296 ls->msgfmt |= LSFMT_USEC;
298 ls->msgfmt |= LSFMT_TYPE;
300 ls->stream_flags |= LSFLAG_ERR_IS_FATAL;
301 ls->types = log_type_mask(&c->types);
303 CLIST_FOR_EACH(struct limit_config *, lim, c->limits)
304 log_apply_limits(ls, lim);
311 log_new_configured(const char *name)
313 struct stream_config *c = stream_find(name);
315 die("Unable to find log stream %s", name);
317 return log_ref_stream(c->ls);
318 return do_new_configured(c);
322 log_configured(const char *name)
324 struct log_stream *ls = log_new_configured(name);
325 struct log_stream *def = log_stream_by_flags(0);
326 log_rm_substream(def, NULL);
327 log_add_substream(def, ls);
328 log_close_stream(ls);
334 #include "ucw/getopt.h"
336 int main(int argc, char **argv)
340 while ((c = cf_getopt(argc, argv, CF_SHORT_OPTS, CF_NO_LONG_OPTS, NULL)) >= 0)
341 die("No options here.");
343 int type = log_register_type("foo");
344 struct log_stream *ls = log_new_configured("combined");
345 for (uns i=0; i<10; i++)
347 msg(L_INFO | ls->regnum | type, "Hello, universe!");